The city's prison population has swelled in recent years after authorities arrested more than 10,200 people in connection with the huge and sometimes violent pro-democracy protests in 2019.

Beijing then imposed a national security law on Hong Kong in 2020 and city officials separately passed a homegrown security law last year.

"National security risks still exist. It is necessary to amend the (prison rules) as soon as possible to prevent and resolve relevant risks in a timely manner," Hong Kong's Security Bureau wrote in a submission to the legislature.

Officials argued that the current visiting system had been abused "by some people using 'humanitarian relief' as a pretext to visit for influencing" prisoners to resist the authorities.

The proposal would also allow prison authorities to apply for a magistrate's warrant to bar a prisoner from meeting specific lawyers to "prevent any risks arising from the abuse of the legal visit system".

Officials said such restrictions are in line with those in the United States, Britain and Australia.

Jailed activist Owen Chow and his lawyer were found guilty last year of flouting prison rules after they failed to use the proper channels to deliver a complaint letter.

The wide-ranging document presented to the legislature also proposed abolishing systems allowing for "private clothes" and "private diet", as well as amending rules on sending and receiving letters.

Almost 10,000 people were in Hong Kong correctional institutions as of March, with a record 3,900 of them not formally convicted of any crime.

Officials say the rule changes will be finalised soon for vetting in the legislature.

Hong Kong authorities have for years put pressure on the small groups that offer material and emotional support to jailed demonstrators.

One prominent organisation, Wall-fare, closed in 2021 after the city's security chief accused it of endangering national security in prisons.